The Flow Cytometry Shared Resource provides state-of-the-art cell sorting and analysis capability to the members of the Kimmel Cancer Center at Thomas Jefferson University. This shared resource is located in a dedicated laboratory space of about 600 sq ft on the 6th floor of the Bluemle Life Sciences Building, centrally positioned on the Thomas Jefferson University campus. The Flow Cytometry Shared Resource is equiped with one Cytomation MoFlo cell high-speed sorter, one Coutler EPICS Elite flow cytometer capable of sorting, one Coulter XL-MCL automated analytical cytometer, one FACS Calibur Benchtop Analyzer, one FACScan Benchtop Analyzer, two Celeron 400 workstations, one Nikon fluorescence microscope, a 30 cu ft 4C refrigerator, and a 10 cu ft -20C freezer. All units are maintained and managed by a dedicated manager/operator. The most commonly used applications are for surface phenotyping and sorting, detection of intracellular cytokines at the single cell level in mixed populations, single cell real time analysis of Ca[2+] mobilization kinetics, studies of apoptosis, cell cycle analysis, and sorting of viable cells in specific stages of the cell cycle. This shared resource allows experimental and data analysis to be performed in a timely manner and with high sensitivity and accuracy. Peer-review, funded cancer center investigators receive priority for the use of this shared resource. Based on increased capabilities for new services, the steady increase in the use of this resource by cancer center members and the recruitment of new investigators, we project that shared resource usage will increase significantly in the near future. In summary, this shared resource plays a critical role in assisting cancer center investigators as they conduct research into the biology and treatment of cancer.